Biology Chapter 8
The process in which electrons from water move through PSII and PSI and ultimately to NADPH is also known as _____________ photophosphorylation.
Noncylic
The production of one molecule of ________ from water during photosynthesis requires several thousand chlorophyll molecules.
Oxygen
For an electron to absorb light energy, it must absorb a(n) _______________ that contains enough energy to overcome the energy difference between the orbital the electron is in, and the one to which it will be boosted.
Photon
Which photosystem's main function is to generate high-energy electrons for the synthesis of ATP?
Photosystem II
The primary electron acceptor for the excited electron leaving photosystem II is a _______ molecule.
Plastoquinone
In a chlorophyll molecule, an excited electron can follow a path around several atoms in the _________ ring, meaning it is delocalized, and thus able to absorb light energy.
Porphyrin
The first stage of the thylakoid (or light-dependent) reactions is the ________ _________
Primary Photoevent
Four stages of the thylakoid reactions in order
Primary Photoevent, Charge Separation, Electron Transport, Chemiosmosis
The reaction center in chloroplasts is a transmembrane ________-pigment complex.
Protein
Which molecule donates electrons for the synthesis of NADPH in chloroplasts?
Reduced ferredoxin
During photosynthesis, glucose is produced via the ________ of CO2.
Reduction
A leaf that appears to be green to the human eye contains pigment molecules that are
Reflecting Green Light
When light strikes a pigment, some wavelengths are absorbed and some are reflected. For instance, a leaf that appears green to the eye ____________ green wavelengths of light
Reflects
In noncyclic photophosphorylation, how much of each product is synthesized?
Roughly equal amounts of ATP and NADPH
During the light dependent reactions of photosynthesis, an excited electron is transferred from chlorophyll in the reaction center to an acceptor molecule; this stage in the thylakoid reactions is also known as charge __________
Seperation
Reduced quinone is a
Strong electron donor
Most plants combine glucose and fructose to produce _________ which is the major transport sugar.
Sucrose
What is ultimately the main source of energy for almost all living cells on Earth?
Sun
In a green plant, the majority of photosynthesis takes place in __.
The leaves
The production of one molecule of O2 during photosynthesis requires how many chlorophyll molecules?
Thousands
The function of the b6-f complex is to pump protons into the _________ space.
Thylakoid
How is the reaction center positioned in the membrane?
Transmembrane Complex
The ATP needed in the Calvin cycle comes from
both cyclic and noncyclic photophosphorylation
Which of the following describes anoxygenic bacteria?
can't produce oxygen, cannot oxidize water
In the visible spectrum, light energy may be absorbed by boosting ___________ to higher atomic energy levels, sometimes called energy shells
electrons
The ATP synthases of chloroplasts and mitochondria are
evolutionary related
The role of the _______-harvesting complex is to directly absorb photons of light.
light
In chloroplasts, electrons ejected from the photosystems do not return to them, which is known as
noncyclic photophosphorylation
Roughly equal amounts of NADPH and ATP are generated in
noncyclic photophosphorylation
The removal of electrons from certain molecules by a beam of light is also known as the __________ effect.
photoelectric
A beam of light can remove electrons from certain molecules, creating electrical current. What is this phenomenon called?
photoelectric effect
The energy content of a __________ is inversely proportional to the wavelength of the light.
photon
In all photosynthetic organisms studied to date, except one class of photosynthetic bacteria, light is captured by clusters of chlorophyll and accessory pigment molecules, which together are called _________
photosystems
Recent studies with the atomic force microscope have shown that PSI and the ATP synthase are not randomly distributed in thylakoid membranes, rather, they seem concentrated
primarily in the connections between grana (the stroma lamellae).
The range and efficiency of photons that a pigment molecule is capable of absorbing constitute its characteristic absorption ________
spectrum
Once a photon is captured by the light harvesting complex, the pigments in it transfer
the energy of excited electrons but not electrons themselves
Jan Baptista ___________ ___________ performed an experiment for which he grew a willow tree in a pot for several years, during which time he kept an exact record of changes in the weight of the soil.
van helmont
Having two different linked photosystems in chloroplasts overcomes the limitations of anoxygenic photosynthesis by allowing the oxidation of __________
water
A particle of light that acts as a discrete bundle of energy is called
A photon
Why is the Calvin cycle also known as C3 photosynthesis?
Because the first molecule in the cycle has 3 carbon atoms
On the stromal side of the thylakoid membrane, two molecules of reduced ____________ donate two electrons for the synthesis of one molecule of NADPH.
Ferredoxin
Photosystem I passes electrons to
Ferredoxin
The third stage of photosynthesis is also called carbon _________
Fixation
Similar to other pigments, carotenoids assist photosynthesis by capturing energy from __________, however, they absorb wavelengths that are not efficiently absorbed by __________. In addition, they scavenge __________ radicals.
Light Chlorophylls Free radicals
During the primary photoevent, a(n) ________ of light is captured by a pigment.
Photon
Almost all photosynthetic organisms capture light using A. lipid-pigment complexes B. individual chlorophyll molecules located in the membrane C. photosystems
Photosystems
Pigment molecules capturing photons in the chloroplast are organized in distinct structures called ___________
Photosystems
The energy used by most living cells comes ultimately from the ___ and is captured by plants, algae, and bacteria through the process of ____________.
Sun Photosynthesis
The inner (internal) membrane of the chloroplast is also called the __________ membrane
Thylakoid
The internal membrane of the chloroplast is also known as the
Thylakoid Membrane
What is the function of the b6-f complex?
To pump protons in the thylakoid space
The __ diagram describes the energy transitions of electrons as they move through the __ reactions.
Z Light
Anoxygenic bacteria have how many photosystems?
1
Consider the net equation that describes the Calvin cycle. How many NADPH are needed to synthesize the two net G3P molecules that can be used to make a glucose molecule?
12
When you take into account the net equation of the Calvin cycle, how many ATP molecules are needed to synthesize two G3P molecules?
18
A Z diagram illustrates how many electron-energizing steps?
2
How many different types of photosystems are found in chloroplasts?
2
How many molecules of G3P are needed to make one molecule of glucose?
2
The reaction center of purple photosynthetic bacteria contains _________(how many) bacteriochlorophyll a molecule(s)
2
Typically, it is considered that the net gain of the Calvin cycle is(are) ______________ molecule(s) of G3P.
2
What is the net gain of the Calvin cycle?
2 G3P
___________ molecules of G3P made during the Calvin cycle can be used to make one molecule of __________
2 Glucose
The wavelength of visible light is
400-740 nm
How many molecules of CO2 need to be bound to molecules of RuBP to produce 12 molecules of PGA in the Calvin cycle?
6
In the Calvin cycle, ____________ molecules of CO2 are bound to the same number of RuBP molecules to produce 12 molecules of PGA.
6
In the Calvin cycle, _____________ molecules of CO2 are bound to the same number of RuBP molecules to produce 12 molecules of PGA.
6
The enhancement effect states that the rate of photosynthesis is fastest when both photosystems are activated. Which wavelength(s) of light would be most appropriate to demonstrate the enhancement effect?
680 nm (red) 700 nm (far red)
How do carotenoids assist in the photosynthetic process? A. By capturing light wavelengths that are not efficiently absorbed by chlorophylls B. By removing electrons from water and passing them on to chlorophyll with the help of light C. By passing on the electron from chlorophyll to an electron acceptor D. By shuffling electrons between different photosystems in the thylakoid membrane depending on their needs
A
How does the structure of chlorophyll enable its photosynthetic function? A. An electron can be delocalized across the porphyrin ring, allowing it to absorb energy B. The hydrocarbon phytol tail creates nonpolar interactions, influencing the three-dimensional shape of the chlorophyll C. Electrons are sequestered in the interior portion of the porphyrin ring, until they can be transferred to another molecule D. The magnesium ion serves as a biological battery, facilitating the synthesis of ATP
A
Which of the following is an accurate description of carotenoids? A. They are made of carbon rings connected to carbon chains with alternating single and double bonds B. They are made of a porphyrin ring connected to a long hydrophobic chain C. They are made a long carbon chain with multiple double bonds at one end and several hydroxyl groups at the other end
A
Which of the following statements about anoxygenic bacteria is not true? A. They can oxidize water. B. They have one photosystem C. They can convert light energy into the energy stored in ATP D. They cannot produce oxygen
A
According to the diagram, which of the following accelerate photosynthesis when light intensity is high? A. Increase in CO2 B. Increase in Temperature C. Decrease in CO2 D. Decrease in Temperature
A B
Chlorophyll ______, Correct Unavailable is the main photosynthetic pigment in plants as it converts light energy into chemical energy; chlorophyll ______, Correct Unavailable acts as an accessory pigment.
A B
Which of the following are phases of the Calvin cycle? A. Carbon fixation B. Regeneration of ribulose bisphosphate C. Reduction and carbohydrate production D. ATP investment E. Polymerization of glucose
A B C
Which of the following are the three stages of photosynthesis in plants? A. Making ATP and NADPH B. Making ribulose-1,5-bisphosphate C. Splitting of H2O D. Capturing energy from the sunlight E. Using ATP and NADPH to produce organic compounds from CO2
A C E
Which of the following (choose all that apply) are necessary for carbon fixation in the Calvin cycle? A. NADPH B. Dark Conditions C. Light Conditions D. ATP
A D
A photon of light has properties of both
A particle and a wave
What occurs during the primary photoevent?
A photon is captured by a pigment in the photosystem
Photophosphorylation produces __________, which stores chemical energy that can be used for the Calvin cycle. Carbon fixation also requires reducing power, which is provided by ____________ produced by photosystem I.
ATP NADPH
The electron transport chain directly associated with photosystem II is used to generate __, while the electron transport chain directly associated with photosystem I is used to generate __.
ATP NADPH
Clorophyll b is an
An accessory pigment
What occurs during the charge separation stage of the thylakoid reactions?
An excited electron is transferred to an acceptor molecule.
Which of the following organisms have only one photosystem?
Anoxygenic bacteria
A photosystem consists of two components, a(n) _________ complex and a(n) ___________ center.
Antenna Reaction
Chlorophyll b has which of the following effects on photosynthesis? A. It has no effect on the proportion of the photons in sunlight that plants can harvest. B. It greatly increases the proportion of the photons in sunlight that plants can harvest. C. It diminishes the proportion of the photons in sunlight that plants can harvest.
B
The formation of organic molecules from carbon dioxide is called A. carbon dioxide fixation B. carbon fixation C. carboxylation D. decarboxylation
B
Which of the following is made during the light-dependent stages of photosynthesis? A. Carbon Dioxide B. NADPH C. Carbon Monoxide D. Water
B
Which of the following pairs is matched incorrectly? A. Carotenoids:accessory pigments B. Chlorophyll b:main photosynthetic pigment in plants. C. Chlorophyll a:only pigment that can act directly to convert light energy into chemical energy
B
Which of the following are parts of a chlorophyll molecule? A. A manganese atom B. A hydrocarbon tail C. A porphyrin ring D. An anchoring protein
B C
Which of the following are parts of the chloroplast? A. Centromeres B. Thylakoids C. Inner Membrane D. Grana E. Stroma F. Cristae
B C D E
The following diagram shows the change in the rate of photosynthesis as a function of the intensity of light under varying conditions. Which of the following statements (choose all that apply) can be concluded based on the following graph? A. The concentration of CO2 does not play a role in determining the rate of photosynthesis B. The rate of photosynthesis is limited by light at low light intensities C. The rate of photosynthesis is limited by the concentration of CO2 at high light intensities D. The rate of photosynthesis remains constant at all light intensities E. The rate of photosynthesis is limited by temperature at high light intensities.
B C E
Which of the following wavelengths of light are preferentially absorbed by chlorophyll molecules? A. Green B. Red C. Yellow D. Violet-Blue
B D
In chloroplasts, several dozen of these kinds of molecules help comprise a light harvesting complex: A. ATP synthases B. manganese clusters C. pigments D. electron transport chains E. NADP+ reductases
C
Photosynthetic pigments in the chloroplast are organized into distinct clusters known as A. Thylakoids B. Stroma C. Photosystems D. Grana
C
Which of the following describes van Helmont's experiment? A. He studied the photosynthesis of purple sulfur bacteria B. He measured the effect of different light intensities, CO2 concentrations and temperatures on the rate of photosynthesis C. He grew a willow in a pot keeping an exact record of the weight of the soil and the tree over several years
C
Which of the following statements best describes the properties of light? A. Light behaves as a very small particle B. Light has properties of both a wave and an elastic spring C. Light has properties of both a particle and a wave D. Light has properties of both a particle and an elastic spring
C
The Calvin cycle is also known as photosynthesis because the first intermediate of the cycle contains three carbon atoms
C3
The first stage of photosynthesis is
Capturing energy from the sunlight
In photosynthesis, glucose is produced via the reduction of which of the following?
Carbon Dioxide
van Niel introduced the term _________ _________ to denote the process of converting CO2 into organic matter using the electrons and protons resulting from the splitting of water.
Carbon Fixation
The Calvin cycle begins with
Carbon fixation using Rubisco
The two most important classes of pigments in chloroplasts are chlorophylls and _____________
Carotenoids
In chloroplasts, the light-harvesting complex is composed of a web of _________ molecules linked together and held tightly in the thylakoid membrane by a matrix of proteins
Chlorophyll
Green plants utilize _____________ a and b to absorb light energy in photosynthesis
Clorophyll
A graph depicting the efficiency of photon absorption by a pigment molecule as a function of photon wavelength is known as the A. photosynthetic spectrum of the pigment B. action spectrum of the pigment C. photoelectric spectrum of the pigment D. absorption spectrum of the pigment
D
According to the generalized equation for photosynthesis proposed by van Niel, CO2 + 2H2A + light energy yields which of the following? A. CH2O + H2O B. 2 CH2O + O2 C. 2CH2O + ATP D. CH2O + H2O + 2A
D
The third and final stage of photosynthesis is also known as which of the following? A. The carbon reactions B. The light-dependent reactions C. The cyclic reactions D. The light-independent reactions
D
Which of the following is not part of chloroplasts? A. Thylakoids B. Grana C. Stroma D. Cristae
D
Which of the following are the two components of a photosystem? A. A chlorophyll pair B. A chlorophyll center C. A carotenoid antenna D. A reaction center E. An antenna complex
D E
Which of the following are used by green plants to absorb light energy? A. Chloroplast c B. Chlorophyll c C. Xanthophyll b D. Chlorophyll a E. Chlorophyll b
D E
The first two stages of photosynthesis require light and are commonly known as the light-__________ reactions.
Dependent
The light-_______ reactions of photosynthesis occur on membranes.
Dependent
The role of the light-harvesting complex is to
Directly absorb photons of light
The electron that is transferred out of the chlorophyll in the reaction center is restored from a nearby weak electron _________
Donor
In the reaction center which of the following excited subatomic particles are transferred to an acceptor?
Electrons
In the light-harvesting complex of the chloroplast, it is excitation ___________, not the electrons themselves, that pass from one pigment molecule to the next.
Energy
What is transferred out of the reaction center?
Excited electrons
True or false: Glucose is the primary output of the Calvin cycle.
False
True or false: The mechanism of ATP synthesis in the ATP synthase of chloroplasts is fundamentally different from the one used in the ATP synthase of mitochondria.
False
The iron-sulfur protein _________ accepts electrons from photosystem I.
Ferredoxin
During photosynthesis, a chlorophyll in the reaction center loses its excited electron. How is that electron restored?
From a nearby weak electron donor
The thick arrow points to which part of the chloroplast?
Grana
In van Niel's generalized equation of photosynthesis, which of the following is the donor of electrons?
H2A
Carbon fixation involves using the protons and electrons generated by the splitting of what molecule to convert CO2 into organic matter?
H2O
The reaction center of photosystem _____________ consists of a core transmembrane complex made of 12-14 protein subunits and two bound P700 chlorophyll molecules
I
According to recent studies, where are PSII and the b6-f complexes located?
In the grana and in borders between the grana and the stroma lamellae
The red arrow points to which part of the chloroplast?
Inner Membrane
How do plants benefit from having two linked photosystems?
It allows them to use electrons from water to reduce NADP+
In a leaf, the thick layer of cells that are rich in chloroplasts is called the
Mesophyll
